Effect of chenodeoxycholate and ursodeoxycholate on nucleation time in human gallbladder bile

The effects of treatment with chenodeoxycholic acid (CDCA) or ursodeoxycholic acid (UDCA) on nucleation time, biliary lipid concentration, and vesicular lipid composition were studied. Gallbladder bile was collected at the time of surgery from 33 cholesterol gallstone patients who were divided into three groups: 16 untreated, 9 pretreated with CDCA (400 mg/day), and 8 pretreated with UDCA (600 mg/day) for 1-3 weeks before surgery. Control bile samples were also collected from nine patients without cholelithiasis. Nucleation time was prolonged significantly in both CDCA- and UDCA-treated groups [12.6 +/- 8.5 (SD) and 21.0 +/- 0 days, respectively] compared with the untreated gallstone group (3.3 +/- 3.2 days). Both treatments significantly decreased the proportion and concentration of both cholesterol and phospholipids present in the vesicular phase. Treatment with UDCA decreased the cholesterol saturation index more than did CDCA at the dose used in this study. In the CDCA-treated group, patients without much change in cholesterol saturation index (greater than 1.0) showed a prolongation of the nucleation time with a significant decrease in vesicular cholesterol concentration, indicating a shift of cholesterol from vesicles to micelles. UDCA-treated patients and CDCA-treated patients with decreased cholesterol saturation index (less than 1.0) showed a greater effect. The authors conclude that UDCA prolongs the nucleation time mainly by decreasing the cholesterol saturation index, whereas CDCA does so by the dual effect of lowering the cholesterol saturation index and shifting cholesterol from vesicles to micelles.

Alteration of bile acid metabolism in two-thirds hepatectomized rat

Bile acid metabolism after two-thirds partial hepatectomy (PH) in rat was studied. Bile acid kinetics (i.e. synthesis rate and pool size) were determined by wash out method combined with gas liquid chromatography, and serum bile acids by gas liquid chromatography-mass spectrometry. Serum bile acid concentration was highest on the third day after PH, as the liver regeneration progressed but it gradually decreased with increasing cholic acid (CA)/chenodeoxycholic acid (CDCA), reflecting impaired hepatic uptake of bile acids and/or cholestasis during the early post-hepatectomy period. Predominance of CA in bile acid synthesis, pool, and biliary secretion was also found. On the third day after PH, liver weight recovered to 66% of the control value, but enhancement of bile acid synthesis was not observed. Consequently, pool size remained at 50% of control. On the seventh day, synthesis of bile acid, especially of CA, was enhanced and pool size and liver weight returned to 68 and 72% of the respective control values. Bile acid synthesis was returned to the control value on the fourteenth day with concomitant restoration of liver weight and bile acid pool size. These changes in bile acid kinetics parallel the events during hepatic regeneration after PH.

Possible factors affecting the cholesterol nucleation time in human bile: a filtration study

This study examined the hypothesis that filtration through the MW 300 kD cut-off membrane (XM-300) may influence factors affecting the cholesterol nucleation time (the appearance time of cholesterol monohydrate crystal). Differences in biliary lipids, biliary protein, mucous glycoprotein and vesicular composition were examined before and after the XM-300 filtration in control and cholesterol gallstone patients. The nucleation time in the cholesterol gallstone patients was significantly faster than that in the control patients. However, the nucleation time in the gallstone patients was significantly prolonged following the XM-300 filtration resulting in a similar value to that of the control patients. No differences in concentrations of total protein, mucous glycoprotein or lipids composition were observed. The nucleation time did not correlate with the total lipid concentration, the concentrations of biliary mucous glycoprotein or total protein. The prolonged nucleation time of gallstone bile by the XM-300 filtration was primarily ascribed to the removal of vesicles, which was confirmed by gel chromatography. It was concluded that vesicles greater than MW 300 kD are primarily responsible for the rapid nucleation time.

Characterization of mucin in the hepatic bile of patients with intrahepatic pigment stones

To investigate the relationship between biliary mucin and ductular stone formation, mucin was isolated from hepatic bile using gel filtration on Sepharose CL-4B. The bile was obtained from 14 patients with stones in various sites of the biliary tract. The hexose content in the excluded fraction was significantly higher in patients with intrahepatic ductular stones (68.7 +/- 20.5 micrograms/mL; mean +/- s.d.) than in those with gall-bladder stones or extrahepatic ductular stones (23.8 +/- 8.1 micrograms/mL, 33.3 +/- 9.5 micrograms/mL; P less than 0.05), suggesting a higher concentration of mucin in the bile of patients with intrahepatic ductular stones. Ion-exchange chromatography on DEAE-Sephacel showed that most mucin from each material was negatively charged and electrophoretic studies indicated that it was composed mainly of high molecular weight (greater than 10(6)), sulfated glycoprotein. These results suggested that the mucin content of hepatic bile might have an important relation to the development of intrahepatic ductular stones.

Fc epsilon receptor II/CD23+ lymphocytes in atopic dermatitis. III. Aberrant control in the in vitro expression of Fc epsilon RII/CD23 on peripheral blood T cells in atopic dermatitis

In vitro Fc epsilon RII expression was examined in patients with atopic dermatitis, those with non-atopic eczematous dermatitis and normal individuals following stimulation of peripheral blood cells with recombinant IL-4 (rIL-4), phytohaemagglutinin (PHA), or PHA plus rIL-2. At various days cells were stained with MoAbs to human lymphocyte Fc epsilon RII and to lymphoid cell-surface antigens and analysed by flow cytometry. rIL-4, but not rIL-2, specifically induced Fc epsilon RII on T cells as well as B cells in atopic dermatitis, eczematous dermatitis and normal individual groups. Both atopics and non-atopics generated comparable proportions of Fc epsilon RII+ T cells (T epsilon cells), whereas the frequency of B cells bearing Fc epsilon RII(B epsilon cells) was significantly higher in patients with extensive atopic dermatitis than in those with mild atopic dermatitis and other subjects. Comparable levels of T epsilon cells were detected in both atopic and non-atopic donors following stimulation of peripheral blood cells with PHA or pre-activation of the cells with PHA plus subsequent incubation with rIL-2. Whereas both CD8+ and CD4+ subsets were present in T epsilon cell populations induced specifically by rIL-4, PHA and PHA plus rIL-2, patients with atopic dermatitis had a greater tendency for Fc epsilon RII expression on CD8+ T cells compared with patients with eczematous dermatitis and normal individuals. Recombinant interferon-gamma (rIFN-gamma), but not rIFN-alpha or prostaglandin E2 (PGE2), suppressed the generation of T epsilon cells by rIL-4 in atopics and non-atopics to the same degree. These results suggest the aberrant control of Fc epsilon RII expression on T cells, especially those bearing CD8, in atopic dermatitis.

Profiling of eicosanoids in inflamed gall bladder wall by gas chromatography with selected-ion monitoring

The profiling of eicosanoids, including prostaglandin E2 (PGE2), prostaglandin F2 alpha (PGF2 alpha), 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha), thromboxane B2 (TXB2) and leukotriene B4 (LTB4), in dog and human gall bladders was carried out by a combination of an effective and convenient clean-up procedure and gas chromatography with selected-ion monitoring. The clean-up procedure was based on the stepwise elution of their methyl ester derivatives from a silica gel column with n-hexane-ethyl acetate and ethyl acetate-methanol in various ratios. The LTB4 methyl ester was eluted with an n-hexane-ethyl acetate (2:1, v/v) fraction because LTB4 is more lipophilic than the other eicosanoids. The present method permitted the quantitation of trace amounts of eicosanoids, including LTB4, present in tissues in the order of pg/mg of protein, without interference from other endogenous substances. In experimental acalculous cholecystitis produced in dog, the levels of eicosanoids (except LTB4) were significantly changed. Of these eicosanoids, the level of 6-keto-PGF1 alpha was significantly higher in the seromuscular layer and correlated with the observed severe morphological changes. In human chronic cholecystitis with gallstones, the level of 6-keto-PGF1 alpha in the mucosal layer was significantly higher than that in the seromuscular layer. These data suggest that prostaglandin I2 may play an important pathophysiological role in the course of cholecystitis.

Significance of different conjugate forms of bilirubin in the formation of pigment gallstones

The aim of the present study was to analyse bile samples from cases with gallstones by high performance liquid chromatography according to the type of stones present, with special reference to the glucoside and xyloside conjugates of bilirubin, and to investigate their deconjugation. The composition of bilirubin conjugates in bile was similar between cholesterol and black pigment stones except that the total bilirubin concentration was about 5 times higher in black pigment stone cases with haemolysis. Unconjugated bilirubin was higher in brown pigment stone cases than in cholesterol stone cases, although total bilirubin concentration was lower in the former. In addition, in brown pigment stone cases, bile contained statistically less bilirubin diglucuronide and more bilirubin diglucoside and monoglucoside than in bile with cholesterol stones (P less than 0.05). Glucoside and xyloside conjugates are also major components, regardless of the types of gallstones present, accounting for as much as 18 to 25%. Incubation experiment revealed that bilirubin diglucuronide was more readily deconjugated than bilirubin diglucoside or bilirubin monoglucoside monoxyloside. Therefore, glucuronide conjugates were likely to be the main source of unconjugated bilirubin in the formation of pigment gallstones.

Fibronectin: a possible factor promoting cholesterol monohydrate crystallization in bile

To examine the hypothesis that fibronectin physiologically present in bile might be a possible nucleating factor, the concentrations of fibronectin in gallbladder bile were determined and its induced effect on nucleation time and on the form of vesicle were examined in bile-model and human gallbladder bile. The gallbladder bile samples taken from patients with cholesterol gallstone had a significantly higher concentration of fibronectin and the faster nucleation time than the control. However, no significant correlation was found between nucleation time and endogenous fibronectin concentration. The addition of 0.5, 1.2, 10 micrograms/ml of fibronectin into two kinds of bile-model significantly shortened the nucleation time in a dose-related manner. Nucleation time was significantly shortened by the addition of 1 microgram/ml exogenous fibronectin into abnormal bile while such an effect was absent in the control. The addition of fibronectin increased the size of vesicles observed by the electron microscope. The results suggest that fibronectin physiologically present in bile may be one of the possible nucleating factors.

Promoting effect of truncal vagotomy on pancreatic carcinogenesis initiated with N-nitrosobis(2-oxopropyl)amine in Syrian golden hamsters

The effect of truncal vagotomy (TV) on pancreatic carcinogenesis initiated with N-nitrosobis(2-oxopropyl)amine (BOP) was investigated in 81 female Syrian golden hamsters. The animals were divided into four groups according to the treatment, groups 1 and 2 serving as non-initiated controls receiving a single s.c. injection of 0.9% NaCl followed by either a sham operation or TV respectively, at week 2. Groups 3 and 4 were given a single s.c. injection of 70 mg/kg body wt of BOP before the sham operation or TV. All hamsters were killed at week 24, and the pancreas, liver and gall bladder tissues were examined histologically. While TV itself caused no significant change in pancreatic weight, the incidence of pancreatic carcinomas in hamsters from group 4 was 48.4%, significantly higher than the 16.7% evident in hamsters from group 3 (P less than 0.05). GLC analysis of the bile acid composition of gall bladder bile from hamsters not receiving carcinogen 1 and 4 months after TV revealed significantly decreased secondary bile acids. The results thus indicated that changes in bile acid composition may be involved in enhancement of BOP-initiated pancreatic carcinogenesis in hamsters by TV.

Impact of recent advances in hepatobiliary imaging techniques on the preoperative diagnosis of carcinoma of the gallbladder

Among 26 patients with gallbladder carcinoma, 11 resected cases were studied retrospectively with respect to the preoperative imaging techniques and the operative procedures employed. Ultrasonography, endoscopic ultrasonography, and computed tomography were valuable in detecting gallbladder carcinoma preoperatively while direct cholangiography and angiography were helpful in designing operative strategy. The ultrasonographic findings were: a polypoid (fungating) mass protruding into the gallbladder lumen in 45%, abnormal thickening of the gallbladder wall in 18%, and a mass in the gallbladder invading adjacent organs in 18% of cases. Approximately 80% was diagnosed preoperatively by ultrasonography. Correct diagnosis was made by computed tomography in 60% of the cases. Endoscopic ultrasonography offered valuable information on the depth of tumor invasion. Direct cholangiography and angiography were useful in assessing the extent of the tumor spread. Recent advances in hepatobiliary imaging techniques, especially ultrasonography and computed tomography, contributed greatly to the detection and evaluation of gallbladder carcinoma at an early and resectable stage.

Pathology of carcinoma of the gallbladder

A clinicopathologic study of 40 cases of carcinoma of the gallbladder is presented. Twenty-six cases resected were assessed retrospectively with respect to the operative procedures employed and the results based on the pathologic findings from the resected specimens. The relationship between clinical features, macroscopic forms of tumor, histological types, liver invasion, and lymph node metastasis were investigated. Papillary, papillary infiltrative and nodular forms were classified as either papillary adenocarcinoma or well-differentiated tubular adenocarcinoma and invasion of the liver and lymph node metastasis were rare. Frequent lymph node metastasis was encountered in the nodular infiltrative form and invasion of the liver was frequently present in the infiltrative form. Invasion of the liver, lymph node metastasis, and the presence of gallstones were less frequent in papillary adenocarcinoma. In contrast, moderately-differentiated tubular adenocarcinoma frequently had lymph node metastasis. Invasion of the liver and lymph node metastasis were, however, present regardless of the histologic types and were more related to the extent of subserosal involvement present. A female preponderance was noted in poorly-differentiated adenocarcinoma. The main reasons for surgery being limited to exploratory laparotomy only or palliative procedures included carcinoma infiltration into the hepatoduodenal ligament, carcinoma extension to the neighboring structures, multiple liver metastases, peritoneal dissemination, large liver invasion, and multiple metastases to the paraaortic lymph nodes.

Hepatolithiasis in East Asia: comparison between Japan and China

The incidence of hepatolithiasis is high throughout East Asia compared with the West, but the marked difference in the relative proportion of hepatolithiasis to all cholelithiasis cases exists even among countries of similar ethnic backgrounds. A retrospective study of cases was conducted in two areas in China with the aim of clarifying the presence of such regional difference in China itself. The relative proportion of hepatolithiasis was 21.2% in Shenyang, 9.2% in Beijing and 4.1% in Fukuoka, Japan. A significant difference in the location of stones was also found between Shenyang, Beijing and Fukuoka. Intra- and extrahepatic hepatolithiasis in all hepatolithiasis cases was 95% in Shenyang and 75% in Beijing. Involvement of both hepatic lobes was found in 73% in Shenyang and less than 60% in the other two, suggesting that hepatolithiasis of the old form or of an advanced stage still lingers in Shenyang. In conclusion, regional differences in the proportion and the type of hepatolithiasis exist in China itself, as well as in the Chinese population in Taiwan, Hong Kong and Singapore, as previously reported. The possible contribution of environmental factors to the occurrence of hepatolithiasis is again emphasized.

Increased lysophosphatidylcholine and pancreatic enzyme content in bile of patients with anomalous pancreaticobiliary ductal junction

A high incidence of inflammation and carcinoma of the biliary tract in patients with anomalous pancreaticobiliary ductal junction has been well documented. The change in biliary phospholipids as a result of the reflux of pancreatic juice into the biliary tract through anomalous pancreaticobiliary ductal junction may be responsible for it. We developed a new method of analysis of phospholipid classes using aminopropyl Bond Elut cartridge for extraction and high-performance liquid chromatography for separation. Satisfactory recovery was achieved (i.e., more than 95% for both phosphatidylcholine and lysophosphatidylcholine). With this method, the bile of 11 patients with anomalous pancreaticobiliary ductal junction was examined. The concentration and proportion of lysophosphatidylcholine in bile were much higher in the presence of anomalous pancreaticobiliary ductal junction than in controls (3.44 +/- 1.50 mmol/L vs. 0.52 +/- 0.25 mmol/L, 60.0% +/- 31.0% vs. 2.3% +/- 1.4% in gallbladder bile; p less than 0.001). In contrast, the concentration of phosphatidylcholine and the sum of phosphatidylcholine and lysophosphatidylcholine in gallbladder bile significantly decreased (p less than 0.001), but in hepatic bile they did not. An inverse correlation was found between the proportion of lysophosphatidylcholine and phospholipid concentration in gallbladder bile. Phospholipase A2 and amylase activities in bile were markedly high. Increased total fatty acid concentration and proportion of unsaturated fatty acid in bile were found. Total bile acid concentration in gallbladder bile was significantly lower than in controls. These results suggest that a considerable amount of lysophosphatidylcholine, which is known to have a cytotoxic effect, isp reduced by phospholipase A2 in refluxing pancreatic juice, and an increased concentration of lysophosphatidylcholine gives rise to cell damage causing mucosal hyperplasia and metaplasia.(ABSTRACT TRUNCATED AT 250 WORDS)

[Localization of HTLV-I-associated antigens in adult T cell leukemia cells and HTLV-I-infected cell line cells]

Localization of HTLV-I-associated antigens was studied in adult T cell leukemia (ATL) cells and HTLV-I-infected cell line cells using monoclonal and human polyclonal antibodies against the viral-related antigens. Two monoclonal antibodies that we obtained by hybridoma technique reacted with HTLV-I-virus core antigens, P19 and P24, respectively. Human anti-HTLV-I-antibodies, which were purified from sera from ATL patients reacted with not only HTLV-I virus particles but also their precursors located in the cytoplasm. In tumor cells freshly isolated from ATL patients, no expression of the virus antigens was observed. When the cells were cultured for several days, the virus antigens were defined in about 3-5% of the cultured cells by the monoclonal antibodies, and in 5-10% by the purified human anti-HTLV-I antibodies. Addition of 5-iodo-2'-deoxyuridine to the culture inhibited cell growth, and at the same time, increased the percentage of the virus antigen-positive cells. Established HTLV-I-infected cell lines showed different cytological profiles from the original ATL cells in the viral replication and morphology.

Manometric and histologic assessment following proctocolectomy and straight enteroanal anastomosis in canines

Serial manometric studies were performed in mongrel dogs before and after total colectomy, mucosal proctectomy and interposed jejunoanal anastomosis without pouch. Fecal continence and body weight gain were clinically satisfactory by 28 weeks after surgery. Even at 28 weeks after the mucosal proctectomy, the mean maximal resting anal sphincter pressure was significantly lower than the preoperative level (p less than 0.001). Neorectal compliance also decreased. The rectoanal inhibitory reflexes were not observed 2 weeks after the mucosal proctectomy but atypical to typical patterns gradually appeared up to 28 weeks following the mucosal proctectomy. Histologic examination showed no injury of anal sphincter muscles. Mild inflammation was found in the neorectal mucosal layer in all animals. Meissner's plexus in rectal muscular cuff was almost completely disrupted. These data suggested that there is certain limitation in restoration of anoneorectal function after mucosal protectomy and enteroanal anastomosis, though with gentle and careful operations.

Esterified and total 7 alpha-hydroxycholesterol in human serum as an indicator for hepatic bile acid synthesis

Serum levels of 7 alpha-hydroxycholesterol and activities of hepatic microsomal cholesterol 7 alpha-hydroxylase in surgical patients were analyzed by capillary gas-liquid chromatography-selected ion monitoring technique using a new internal standard, 5 alpha-cholestane-3 beta, 7 beta-diol. We found that concentrations of 7 alpha-hydroxycholesterol obtained after alkaline hydrolysis were higher than those without alkaline hydrolysis, indicating that a considerable amount of 7 alpha-hydroxycholesterol in human serum is present in esterified form. Esterified 7 alpha-hydroxycholesterol could also be quantitatively hydrolyzed with cholesterol esterase, suggesting that fatty acid is bound at the 3 beta-position of the cholestenediol. The serum levels of esterified and free 7 alpha-hydroxycholesterol in patients with cholelithiasis were 198.0 +/- 90.3 and 48.3 +/- 19.8 pmol/ml (mean +/- SD), respectively, and were similar to those in patients without hepatobiliary diseases. After treatment with chenodeoxycholic acid (300 mg per day) for 7 to 10 days, esterified and free 7 alpha-hydroxycholesterol levels decreased to 64.9 +/- 33.6 and 20.5 +/- 11.1 pmol/ml, respectively. Activity of cholesterol 7 alpha-hydroxylase was also inhibited. Treatment with ursodeoxycholic acid (600 mg per day) for 7 to 10 days had no inhibitory effect on serum 7 alpha-hydroxycholesterol levels and the enzyme activity. In all groups, high correlations were found between the activity of cholesterol 7 alpha-hydroxylase and serum levels of 7 alpha-hydroxycholesterol: free (r = 0.71, n = 38, P less than 0.001); esterified (r = 0.87, n = 38, P less than 0.001); total (r = 0.87, n = 38, P less than 0.001). Esterified and total 7 alpha-hydroxycholesterol was more highly correlated with the enzyme activity than the free form. We conclude that a significant amount of 3 beta-acyl esters of 7 alpha-hydroxycholesterol is present in human serum and that serum levels of esterified and/or total 7 alpha-hydroxycholesterol are likely to reflect the activity of hepatic cholesterol 7 alpha-hydroxylase and thus the amount of primary bile acids synthesized in the liver.

Effects of bile acid feeding on hepatic deoxycholate 7 alpha-hydroxylase activity in the hamster

In order to investigate the effects of bile acid feeding on hepatic microsomal deoxycholate 7 alpha-hydroxylase activity, three different bile acids were administered (0.2% w/w in chow) to hamsters for two weeks. Deoxycholate 7 alpha-hydroxylase activity was increased markedly by feeding of cholic acid (CA) and slightly by deoxycholic acid (DCA). Chenodeoxycholic acid (CDCA) had little effect on the enzyme activity. Feeding each of the bile acids significantly inhibited the activity of cholesterol 7 alpha-hydroxylase in the order CDCA greater than or equal to DCA greater than CA. There was no correlation between deoxycholate 7 alpha-hydroxylase activity and cholesterol 7 alpha-hydroxylase activity. It is concluded that the activity of deoxycholate 7 alpha-hydroxylase is up-regulated by feeding DCA and CA and that the mechanism seems to be different from that of cholesterol 7 alpha-hydroxylase. The increased activity of hepatic deoxycholate 7 alpha-hydroxylase by CA and DCA should be beneficial in minimizing the toxic effects of DCA in the hamster.

Biliary lipids and bile acid composition before and after endoscopic sphincterotomy

The effect induced by endoscopic sphincterotomy on biliary lipids and bile acid composition was examined by following up the seven patients prior to early (1-2 week) and late (0.5-1 year) after the endoscopic sphincterotomy. The concentrations of total bile acids, phospholipid and cholesterol were essentially constant throughout the one-year observation period. Cholesterol saturation indices were not significantly altered. No bile acid concentration changed significantly. The results indicate that endoscopic sphincterotomy has little undesirable effect on the biliary lipids and bile acid compositions over an observed period.

Homogenous junctional sequence of the V14+ T-cell antigen receptor alpha chain expanded in unprimed mice

Nucleotide sequences of VJ (variable-joining) junctional regions of V14+ alpha-chain T-cell receptor genes show that most V alpha 14+ T cells use one alpha chain (V alpha 14J alpha 281 with a one-nucleotide N region, which is frequently used in keyhole limpet hemocyanin-specific suppressor T-cell hybridomas) in unprimed mice. Moreover, the frequency of this alpha-chain expression was greater than 1.5% of the total alpha chains found in laboratory strains, including B10 congenic mice. This is about 10(4) times higher than was expected. The V14J281 alpha-chain expression was relatively low but was significant in CD4+/CD8+ immature thymocytes and became quite high in mature single-positive T cells, implying that this alpha chain is selected during T-cell maturation. V14J281 expression increased with time after birth and reached a maximum at around 5 weeks of age. The ligand seems to be a self molecule and to be present in laboratory strains but to be absent in a wild mouse, Mus musculus molossinus, because bone marrow chimeras clearly showed that bone marrow cells derived from Mus musculus molossinus negative for this alpha chain raised V14J281-positive T cells in a C57BL/6 environment. The above results suggest that there are some selection mechanisms for this cell type other than those for conventional alpha beta T cells and also that the homogenous VJ junction of the V14J281 alpha chain plays a pivotal role in the selection of the T cell and its ligand reactivity.

Unscheduled DNA synthesis after treatment with 20-methylcholanthrene and N-nitrosodimethylamine in primary culture of human gallbladder epithelial cells

Unscheduled DNA synthesis (UDS) induced by treatment with 20-methylcholanthrene (MCA) and N-nitrosodimethylamine (DMN) was measured in cultured human gallbladder epithelial cells. MCA induced UDS very efficiently, while DMN was far less effective than MCA. Addition of rat S9 mixture did not affect the amount of UDS by the chemicals. Differences between the present results in human cells and our previous findings in bovine cells could be due to species and tissue specificity.

Simultaneous determination of keto and non-keto bile acids in human serum by gas chromatography with selected ion monitoring

A reliable method for the simultaneous determination of keto and non-keto bile acids in human serum was developed. Carbonyl substituents of bile acid ethyl esters were converted into methyloxime and hydroxyl substituents into dimethylethylsilyl ethers and the products were analysed directly by capillary gas chromatography with selected ion monitoring using [2H4]chenodeoxycholic and [2H4]3 alpha-hydroxy-7-oxo-5 beta-cholanoic acids as internal standards. The bile acid peaks on the selected ion chromatogram were separated without interference from endogenous substances present in serum. Recoveries of individual keto bile acids added to serum range from 74.4 to 94.7% with a mean of 87.1%. Eight kinds of keto bile acids not previously found in sera of normal subjects, namely 3-oxo-, 3-oxo-7 alpha-hydroxy-, 3-oxo-12 alpha-hydroxy-, 3 alpha-hydroxy-7-oxo, 3 alpha-hydroxy-12-oxo-, 3-oxo-7 alpha,12 alpha-dihydroxy-, 3 alpha,7 alpha-dihydroxy-12-oxo- and 3 alpha,12 alpha-dihydroxy-7-oxo-5 beta-cholanoic acids were identified and quantified. The total concentration of keto bile acids was found to be 0.16 +/- 0.08 nmol/ml and constituted 2.9 +/- 1.5% of that of the usual non-keto bile acids in peripheral venous serum.